Question

In an experiment with a convex lens, the plot of the image distance (ν′) against the object distance (μ′) measured from the focus gives a curve ν′μ′ = 225. If all the distances are measured in cm. The magnitude of the focal length of the lens is _______ cm.

Answer 1

$vu = f^2$ (by Newton's formula)

$f^2$ = 225

$f = 15 cm$